This tank may be an exception. It has a ridiculous amount of people playing it despite everyone bashing it. VBaddict puts it at positon 31 for battles played out of however many tanks are in the game. That's not bad. Okay, maybe it's all for credit farming, but I think if it was as bad as people say it is, no one would be playing it.

This. The T26E5 has no chance against something like the Type 5. The weak spots are 250mm, and 260mm. The max pen for the T26E5 is only 259mm with APCR. Even the hatch is effectively 250+ unless your on higher ground. Even if it does pen (by some miracle) it's only 240 with a low roll 200... It has no stopping power. It's the same case with the E100, and the Maus. Unless you get the lower plate un-angled; your history. The ability to fight these monster is not something to be overlooked when shopping for a premium tank.

battles don't really say a lot about how good a premium tank is because the only way people get them is 1.buy them with gold or money 2.earn them in some kind of mission 3. if WG gives them for free to everyone
the t34 is(or at least was) available for gold purchase in the tech tree, not a lot of other alternative premiums were. This means its easier to acquire via purchase.
there was the t34b missions, cant remember if they had missions for the regular t34 but that also means even more chances for somebody to own it. Then consider it used to be a standard tank but switched to premium so players at that time also had yet another opportunity to get it.
Given all that info it is going to be one of the most owned t8 premiums if not the most. If people own it they are likely to play it even if the tank itself isn't competitive at all. It does make good credits and trains American heavy crews, it serves that purpose so people play it. Very few play it because they consider it a good tank.